Table III.
Associations between anthropometric measures and time-to-pregnancy in women from the S-PRESTO study, 2015-2017
| Anthropometric measures | n | Pregnancies | Cycles | Model 1a |
Model 2b |
Model 3c |
|||
|---|---|---|---|---|---|---|---|---|---|
| FR | 95% CI | FR | 95% CI | FR | 95% CI | ||||
| Body mass index (kg/m2) | |||||||||
| <18.5 | 43 | 14 | 80 | 0.67 | 0.38, 1.17 | 0.60 | 0.34, 1.06 | 0.59 | 0.33, 1.06 |
| 18.5-22.9 | 230 | 95 | 539 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| 23-27.4 | 130 | 38 | 215 | 0.70 | 0.48, 1.03 | 0.66 | 0.45, 0.97 | 0.64 | 0.44, 0.95 |
| ≥27.5 | 74 | 21 | 102 | 0.66 | 0.41, 1.06 | 0.53 | 0.31, 0.89 | 0.54 | 0.31, 0.91 |
| Sum of skinfold thickness (mm) | |||||||||
| Q1 (25.0-52.9) | 117 | 46 | 254 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| Q2 (53.0-70.0) | 118 | 49 | 284 | 1.09 | 0.73, 1.62 | 1.11 | 0.73, 1.67 | 1.03 | 0.67, 1.57 |
| Q3 (70.1-90.0) | 118 | 42 | 232 | 0.91 | 0.60, 1.39 | 0.96 | 0.62, 1.46 | 0.91 | 0.56, 1.50 |
| Q4 (90.1-151.8) | 118 | 30 | 149 | 0.62 | 0.39, 0.98 | 0.58 | 0.36, 0.95 | 0.60 | 0.30, 1.20 |
| Total body fat (%) | |||||||||
| Q1 (13.6-27.2) | 96 | 39 | 290 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| Q2 (27.3-32.9) | 97 | 36 | 192 | 0.81 | 0.45, 1.44 | 0.83 | 0.52, 1.32 | 0.74 | 0.46, 1.20 |
| Q3 (33.0-39.7) | 97 | 25 | 200 | 0.62 | 0.31, 1.22 | 0.56 | 0.32, 0.98 | 0.50 | 0.25, 0.97 |
| Q4 (39.8-61.3) | 96 | 23 | 144 | 0.54 | 0.26, 1.13 | 0.43 | 0.24, 0.80 | 0.40 | 0.16, 0.97 |
| Waist circumference (cm) | |||||||||
| ≤74 | 110 | 40 | 205 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| 75-80 | 130 | 50 | 235 | 0.97 | 0.64, 1.47 | 0.94 | 0.59, 1.48 | 0.76 | 0.48, 1.22 |
| 81-86 | 100 | 37 | 160 | 0.94 | 0.60, 1.48 | 1.01 | 0.63, 1.62 | 0.88 | 0.52, 1.50 |
| ≥87 | 135 | 40 | 169 | 0.75 | 0.49, 1.17 | 0.66 | 0.40, 1.08 | 0.74 | 0.37, 1.49 |
| Waist-to-hip ratio | |||||||||
| <0.80 | 74 | 27 | 137 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| 0.80-0.84 | 131 | 39 | 188 | 0.81 | 0.56, 1.18 | 0.79 | 0.53, 1.18 | 0.76 | 0.52, 1.11 |
| ≥0.85 | 270 | 101 | 604 | 1.18 | 0.77, 1.80 | 1.19 | 0.75, 1.87 | 1.16 | 0.73, 1.83 |
| Waist-to-height ratio | |||||||||
| ≤0.5 | 217 | 78 | 416 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| >0.5 | 258 | 89 | 513 | 0.93 | 0.69, 1.26 | 0.92 | 0.66, 1.27 | 0.92 | 0.66, 1.27 |
| A body shape index (m11/6 /kg2/3) | |||||||||
| Q1 (0.064-0.077) | 118 | 38 | 170 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| Q2 (0.078-0.080) | 119 | 45 | 246 | 0.97 | 0.63, 1.49 | 0.94 | 0.61, 1.45 | 0.94 | 0.61, 1.45 |
| Q3 (0.081-0.084) | 119 | 42 | 279 | 0.91 | 0.59, 1.41 | 0.85 | 0.55, 1.32 | 0.85 | 0.55, 1.32 |
| Q4 (0.085-0.094) | 119 | 42 | 234 | 0.89 | 0.57, 1.38 | 0.90 | 0.58, 1.40 | 0.90 | 0.58, 1.40 |
Data were analyzed using discrete-time proportional hazards models. S-PRESTO, Singapore PREconception Study of long-Term maternal and child Outcomes; FR, fecundability ratio; CI, confidence interval
a
Crude model
b
Adjusted for age, ethnicity, education, parity and cycle length
c
Adjusted for model 2, plus waist-to-hip ratio (in models for body mass index) and body mass index (in all models except waist-to-height ratio and A body shape index models)